refactor: Use mocks for x/authz testing (#12799)

## Description

Closes: #12761 



---

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- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [ ] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/main/CONTRIBUTING.md#pr-targeting))
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- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/main/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/main/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
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### Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

x/authz/simulation/decoder_test.go

@@ -7,28 +7,28 @@ import (
 
 	"github.com/stretchr/testify/require"
 
-	"cosmossdk.io/depinject"
-	"github.com/cosmos/cosmos-sdk/codec"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/kv"
 	"github.com/cosmos/cosmos-sdk/x/authz"
 	"github.com/cosmos/cosmos-sdk/x/authz/keeper"
+	authzmodule "github.com/cosmos/cosmos-sdk/x/authz/module"
 	"github.com/cosmos/cosmos-sdk/x/authz/simulation"
-	"github.com/cosmos/cosmos-sdk/x/authz/testutil"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
+
+	moduletestutil "github.com/cosmos/cosmos-sdk/types/module/testutil"
 )
 
 func TestDecodeStore(t *testing.T) {
-	var cdc codec.Codec
-	depinject.Inject(testutil.AppConfig, &cdc)
+	encCfg := moduletestutil.MakeTestEncodingConfig(authzmodule.AppModuleBasic{})
+	banktypes.RegisterInterfaces(encCfg.InterfaceRegistry)
 
-	dec := simulation.NewDecodeStore(cdc)
+	dec := simulation.NewDecodeStore(encCfg.Codec)
 
 	now := time.Now().UTC()
 	e := now.Add(1)
 	sendAuthz := banktypes.NewSendAuthorization(sdk.NewCoins(sdk.NewInt64Coin("foo", 123)), nil)
 	grant, _ := authz.NewGrant(now, sendAuthz, &e)
-	grantBz, err := cdc.Marshal(&grant)
+	grantBz, err := encCfg.Codec.Marshal(&grant)
 	require.NoError(t, err)
 	kvPairs := kv.Pairs{
 		Pairs: []kv.Pair{

x/authz/simulation/genesis_test.go

@@ -7,26 +7,27 @@ import (
 
 	"github.com/stretchr/testify/require"
 
-	"cosmossdk.io/depinject"
 	sdkmath "cosmossdk.io/math"
-	"github.com/cosmos/cosmos-sdk/codec"
 	"github.com/cosmos/cosmos-sdk/types/module"
 	simtypes "github.com/cosmos/cosmos-sdk/types/simulation"
 	"github.com/cosmos/cosmos-sdk/x/authz"
+	authzmodule "github.com/cosmos/cosmos-sdk/x/authz/module"
 	"github.com/cosmos/cosmos-sdk/x/authz/simulation"
-	"github.com/cosmos/cosmos-sdk/x/authz/testutil"
+	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
+
+	moduletestutil "github.com/cosmos/cosmos-sdk/types/module/testutil"
 )
 
 func TestRandomizedGenState(t *testing.T) {
-	var cdc codec.Codec
-	depinject.Inject(testutil.AppConfig, &cdc)
+	encCfg := moduletestutil.MakeTestEncodingConfig(authzmodule.AppModuleBasic{})
+	banktypes.RegisterInterfaces(encCfg.InterfaceRegistry)
 
 	s := rand.NewSource(1)
 	r := rand.New(s)
 
 	simState := module.SimulationState{
 		AppParams:    make(simtypes.AppParams),
-		Cdc:          cdc,
+		Cdc:          encCfg.Codec,
 		Rand:         r,
 		NumBonded:    3,
 		Accounts:     simtypes.RandomAccounts(r, 3),

x/authz/simulation/operations_test.go

@@ -23,7 +23,6 @@ import (
 	bankkeeper "github.com/cosmos/cosmos-sdk/x/bank/keeper"
 	banktestutil "github.com/cosmos/cosmos-sdk/x/bank/testutil"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
-	stakingkeeper "github.com/cosmos/cosmos-sdk/x/staking/keeper"
 )
 
 type SimTestSuite struct {
@@ -37,7 +36,6 @@ type SimTestSuite struct {
 	interfaceRegistry codectypes.InterfaceRegistry
 	accountKeeper     authkeeper.AccountKeeper
 	bankKeeper        bankkeeper.Keeper
-	stakingKeeper     *stakingkeeper.Keeper
 	authzKeeper       authzkeeper.Keeper
 }
 
@@ -49,7 +47,6 @@ func (suite *SimTestSuite) SetupTest() {
 		&suite.interfaceRegistry,
 		&suite.accountKeeper,
 		&suite.bankKeeper,
-		&suite.stakingKeeper,
 		&suite.authzKeeper,
 	)
 	suite.Require().NoError(err)
@@ -98,7 +95,7 @@ func (suite *SimTestSuite) TestWeightedOperations() {
 func (suite *SimTestSuite) getTestingAccounts(r *rand.Rand, n int) []simtypes.Account {
 	accounts := simtypes.RandomAccounts(r, n)
 
-	initAmt := suite.stakingKeeper.TokensFromConsensusPower(suite.ctx, 200000)
+	initAmt := sdk.TokensFromConsensusPower(200000, sdk.DefaultPowerReduction)
 	initCoins := sdk.NewCoins(sdk.NewCoin("stake", initAmt))
 
 	// add coins to the accounts
@@ -156,7 +153,7 @@ func (suite *SimTestSuite) TestSimulateRevoke() {
 		},
 	})
 
-	initAmt := suite.stakingKeeper.TokensFromConsensusPower(suite.ctx, 200000)
+	initAmt := sdk.TokensFromConsensusPower(200000, sdk.DefaultPowerReduction)
 	initCoins := sdk.NewCoins(sdk.NewCoin("stake", initAmt))
 
 	granter := accounts[0]
@@ -191,7 +188,7 @@ func (suite *SimTestSuite) TestSimulateExec() {
 	// begin a new block
 	suite.app.BeginBlock(abci.RequestBeginBlock{Header: tmproto.Header{Height: suite.app.LastBlockHeight() + 1, AppHash: suite.app.LastCommitID().Hash}})
 
-	initAmt := suite.stakingKeeper.TokensFromConsensusPower(suite.ctx, 200000)
+	initAmt := sdk.TokensFromConsensusPower(200000, sdk.DefaultPowerReduction)
 	initCoins := sdk.NewCoins(sdk.NewCoin("stake", initAmt))
 
 	granter := accounts[0]